When we first purchased our swing set, it looked like this.
No one has played on our swing set this summer. When my kids have friends over they may swing for a few minutes, but basically I have been staring at the thing all of June and July wondering what I should replace it with that will encourage some outdoor play. We have a yard that is large by Chicago standards but still pretty tiny so they can't go play soccer out there, they need something to facilitate pretend play. I purchased a large painter's drop cloth and lay it over the two large rectangle sides, securing it with duct tape. Then I cut the excess off and lay that around the two triangle sides. I used safety pins and tape again to make it tight. After that I just sewed it together using strong thread. I decorated it with some patches I sewed that have what I thought looked like Native American symbols and colors. (red, yellow, green and brown only.) I used craft felt for the patches. They are made from a synthetic material that I figure will be somewhat waterproof. I cut a door out and pinned some ribbon on so they can roll it up or have it hang down. It has survived one or two rainstorms so far withoout wrinkling or falling apart but of course this is an experimental project and I am not sure what winter will do to our little fort.